1. Field of the Invention
This invention relates to a stapler, and in particular to a surgical stapler which is primarily intended for use in the interconnecting of spinal vertebrae.
While the thrust of the following is toward the use of the stapler for interconnecting adjacent vertebrae, it will be appreciated that the stapler can be used in a similar manner to interconnect any adjacent penetrable elements.
2. Discussion of the Prior Art
Back problems and more specifically problems involving the discs located between the vertebrae are responsible for much pain and suffering. When a disc is ruptured or otherwise damaged, one solution to the problem has been to remove the disc. At present, the resulting space is often left empty, causing instability and pain due to arthritis. In some cases, the resulting space has been filled with bone blocks, or dowels, taken from another area of the patient's body or from a cadaver, or filled with a prosthesis of the type disclosed for example by Canadian Pat. No. 992,235, issued to Cutter Laboratories, Inc. on July 6, 1976, and U.S. Pat. No. 3,875,595, issued to E. C. Froning on April 8, 1975. The insertion of a plastic cushion between the two vertebrae bodies is unlikely to correct the instability, since such a foreign body will probably be dislodged.
Bone grafting, either between the bodies or along the posterior arches of vertebrae has met with limited success. Because there is a difference in hardness between the graft bone and the vertebrae which causes wear, even if cancellous surfaces have been carefully opposed, the union between the graft bone and the vertebrae often fails. Stalactities and stalagmites grow out of the grafted bone irritating roots in the area. Patients often complain that they have the impression that the disc has been replaced with a cement block.
Thus, it is readily apparent that there exists a need for an alternative method of interconnecting the vertebrae following disc removal. There is also a need for a device for performing such an operation. The object of the present invention is to provide a stapler, which can be used to interconnect adjacent articles such as vertebrae.